1. Field of the Invention
The present invention relates to DC electric motors.
2. Related Art
As energy costs continue to rise and supplies dwindle there is a substantial need for more efficient use of energy, particularly for electric motors. Electric motors power many devices and thus improvements in power output from motors for a given input energy would mean significant savings in energy costs.
One usage in particular that would benefit from an improved electric motor is that of electric vehicles. Although electric vehicles have been around for over one hundred years, they have only recently begun to become widely used. Improvements in electric motor power output would help electric cars become even more practical and accepted in the marketplace.
One problem that existing electric vehicles face is their higher purchase price compared to conventional gas- or diesel-powered vehicles. This is due in part to the expensive electric motors that such vehicles use. The design of such motors is simple but their construction is very complex. In addition the control systems for such motors are complex, because of the requirements for high voltage and current and in particular the high in-rush currents involved. Finally, present electric vehicle motors require a complex transmission system.
Motors having electromagnetic coils without metal cores have been used before, for example in ‘pancake’ type motors generally used in low power applications. However, non-magnetizable core materials such as plastics have not been used for high power motors.
What is needed in the art are new ideas for building and controlling electric motors to produce a more energy-efficient electric motor.